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Green Oxidation on Silver at casting pores

Hello

We make copper and silver (3µm + 3µm) on aluminumdiecasting-parts, after transportation from Sweden to estonia with boat we found into the castingpores green oxdation. Who can help me ?

Schmidt
plating shop - Nürnberg, Bavaria, Germany
2005

I am not a plating expert but I do have a lot of experience with castings including die castings. We had a similar problem with anodized aluminum castings except that it was a white oxide growth. Small pores in the cast skin tend to trap many things. In the case of anodized aluminum, they would trap some acid from the anodize process that would not get rinsed out and would later lead to corrosion. The easy method is to impregnate before plating. If you use a very good and knowledgeable impregnation service, there will not be any problems with surface appearance or plating bath contamination. The other approach would be an airless spray or high pressure spray rinse after plating or possibly an ultrasonic rinse.

Pat Reid
- Costa Mesa, California, USA
2005